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Striking difference in response to expanding brood parasites by birds in western and eastern Beringia
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Vladimir Dinets Kristaps Sokolovskis Daniel Hanley Mark E. Hauber 《Journal of Field Ornithology》2018,89(2):117-125
Two species of obligate brood‐parasitic Cuculus cuckoos are expanding their ranges in Beringia. Both now breed on the Asian side, close to the Bering Strait, and are found in Alaska during the breeding season. From May to July 2017, we used painted 3D‐printed model eggs of two cuckoo host‐races breeding in northeastern Siberia to test behavioral responses of native songbirds on both sides of the Bering Strait, with particular attention to species that are known cuckoo hosts in their Siberian range. Each host nest was tested after the second egg was laid and, if possible, again 4 days later with a model of a different type. Although our Siberian study site was also outside the known breeding ranges of the cuckoos, we found that Siberian birds had strong anti‐parasite responses, with 14 of 22 models rejected. In contrast, birds in Alaska had virtually no detectable anti‐parasite behaviors, with only one of 96 models rejected; the rejecters were Red‐throated Pipits (Anthus cervinus). Such differences suggest that the cuckoos might successfully parasitize naïve hosts and become established in North America whether or not their historic host species are widely available. 相似文献
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Gueorgui Kratassiouk Linda L. Pritchard Sylvain Cuvellier Andrii Vislovukh Qingwei Meng Regina Groisman 《Cell cycle (Georgetown, Tex.)》2016,15(5):667-677
MicroRNAs (miRNAs) in the AGO-containing RISC complex control messenger RNA (mRNA) translation by binding to mRNA 3′ untranslated region (3′UTR). The relationship between miRNAs and other regulatory factors that also bind to mRNA 3′UTR, such as CPEB1 (cytoplasmic polyadenylation element-binding protein), remains elusive. We found that both CPEB1 and miR-15b control the expression of WEE1, a key mammalian cell cycle regulator. Together, they repress WEE1 protein expression during G1 and S-phase. Interestingly, the 2 factors lose their inhibitory activity at the G2/M transition, at the time of the cell cycle when WEE1 expression is maximal, and, moreover, rather activate WEE1 translation in a synergistic manner. Our data show that translational regulation by RISC and CPEB1 is essential in cell cycle control and, most importantly, is coordinated, and can be switched from inhibition to activation during the cell cycle. 相似文献
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Andrii Fatiukha Valentyna Klymiuk Zvi Peleg Yehoshua Saranga Ismail Cakmak Tamar Krugman Abraham B. Korol Tzion Fahima 《The Plant journal : for cell and molecular biology》2020,101(3):555-572
Dissection of the genetic basis of wheat ionome is crucial for understanding the physiological and biochemical processes underlying mineral accumulation in seeds, as well as for efficient crop breeding. Most of the elements essential for plants are metals stored in seeds as chelate complexes with phytic acid or sulfur‐containing compounds. We assume that the involvement of phosphorus and sulfur in metal chelation is the reason for strong phenotypic correlations within ionome. Adjustment of element concentrations for the effect of variation in phosphorus and sulfur seed content resulted in drastic change of phenotypic correlations between the elements. The genetic architecture of wheat grain ionome was characterized by quantitative trait loci (QTL) analysis using a cross between durum and wild emmer wheat. QTL analysis of the adjusted traits and two‐trait analysis of the initial traits paired with either P or S considerably improved QTL detection power and accuracy, resulting in the identification of 105 QTLs and 617 QTL effects for 11 elements. Candidate gene search revealed some potential functional associations between QTLs and corresponding genes within their intervals. Thus, we have shown that accounting for variation in P and S is crucial for understanding of the physiological and genetic regulation of mineral composition of wheat grain ionome and can be implemented for other plants. 相似文献
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Magnetic Resonance Elastography (MRE) is an emerging imaging modality for quantifying soft tissue elasticity deduced from displacement measurements within the tissue obtained by phase sensitive Magnetic Resonance Imaging (MRI) techniques. MRE has potential to detect a range of pathologies, diseases and cancer formations, especially tumors. The mechanical model commonly used in MRE is linear viscoelasticity (VE). An alternative Rayleigh damping (RD) model for soft tissue attenuation is used with a subspace-based nonlinear inversion (SNLI) algorithm to reconstruct viscoelastic properties, energy attenuation mechanisms and concomitant damping behavior of the tissue-simulating phantoms. This research performs a thorough evaluation of the RD model in MRE focusing on unique identification of RD parameters, μI and ρI. 相似文献
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Andrii K. Melnyk Olexandr V. Sukhoveev Lyudmyla A. Kononets Olexandr M. Khilchevsky Valery P. Kukhar 《Journal of liposome research》2016,26(1):80-86
Comparative properties of lecithin-based liposomes prepared from the mixed phospholipids of sunflower seeds, soybean and egg yolk were investigated by electron paramagnetic resonance (EPR) spectroscopy. For these investigations, stable nitroxide radicals, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl 5,7-dimethyladamantane-1-carboxylate (DMAC-TEMPO), 5-doxylstearic acid (5-DSA) and 16-doxylstearic acid (16-DSA) were used as spin probes. Binding of the spin probes to the liposome membranes resulted in a substantial increase of the apparent rotational diffusion correlation times. The EPR spectra of the incorporated nitroxides underwent temperature-dependent changes. For every spin probe, values of apparent enthalpy and entropy of activation were calculated from the temperature dependence of rotational diffusion correlation times via Arrhenius equation. In case of DMAC-TEMPO, the data point to differences between the phospholipid bilayer of liposomes derived from sunflower and soy lecithin, and some similarity between the sunflower and egg yolk liposomes. Anisotropic hyperfine interaction constants of DMAC-TEMPO and 16-DSA included in the liposomes have been analyzed and attributed to different micropolarity of the surroundings of the spin probes. The kinetics of EPR signal decay of DMAC-TEMPO in the presence of 2,2′-azobis(2-amidinopropane) suggest the better stability of the sunflower liposomes to lipid peroxidation as compared to the liposomes prepared from soy lecithin. 相似文献
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Xylose and cellobiose fermentation to ethanol by the thermotolerant methylotrophic yeast Hansenula polymorpha 总被引:3,自引:0,他引:3
Wild-type strains of the thermotolerant methylotrophic yeast Hansenula polymorpha are able to ferment glucose, cellobiose and xylose to ethanol. H. polymorpha most actively fermented sugars to ethanol at 37 degrees C, whereas the well-known xylose-fermenting yeast Pichia stipitis could not effectively ferment carbon substrates at this temperature. H. polymorpha even could ferment both glucose and xylose up to 45 degrees C. This species appeared to be more ethanol tolerant than P. stipitis but more susceptible than Saccharomyces cerevisiae. A riboflavin-deficient mutant of H. polymorpha increased its ethanol productivity from glucose and xylose under suboptimal supply with riboflavin. Mutants of H. polymorpha defective in alcohol dehydrogenase activity produced lower amounts of ethanol from glucose, whereas levels of ethanol production from xylose were identical for the wild-type strain and the alcohol dehydrogenase-defective mutant. 相似文献
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Background
Graves’ disease (GD) is a common cause of hyperthyroidism resulting in development of thyrotoxic heart disease (THD).Objectives
to assess cardiovascular disorders and health related quality of life (HRQoL) in patients with THD secondary to GD.Patients and Methods
All patients diagnosed with THD secondary to GD between January 2011 and December 2013 were eligible for this study. Clinical assessment was performed at baseline and at the follow-up visit after the restoring of euthyroid state. HRQoL was studied with a questionnaire EQ-5D-5L.Results
Follow-up data were available for 61 patients, but only 30 patients with THD secondary to GD were consented to participate in investigation of their HRQoL. The frequency of cardiovascular complications was significantly reduced as compared before and after the antithyroid therapy as follows: resting heart rate (122 vs. 74 bpm), blood pressure: systolic (155 vs. 123 mm Hg), diastolic (83 vs. 66 mm Hg), supraventricular premature contractions (71% vs. 7%), atrial fibrillation (72% vs. 25%), congestive heart failure (69% vs. 20%), thyrotoxic cardiomyopathy (77% vs. 26%), all p<0.01. Anti-TSH receptor antibodies were determined as independent predictor of left ventricular geometry changes, (b-coefficient = 0.04, 95%CI 0.01–0.07, p = 0.02). HRQoL was improved in all domains and self-rated health increased from 43 to 75 units by visual analogue score (p<0.001).Conclusions
Restoring of euthyroid state in patients with GD is associated with significant elimination of cardiovascular disorders and improvement of HRQoL. To our knowledge this is the first study evaluating Ukrainian patients with THD secondary to GD with focus on HRQoL. 相似文献10.
SC Su J Seo JQ Pan BA Samuels A Rudenko M Ericsson RL Neve DT Yue LH Tsai 《Neuron》2012,75(4):675-687
N-type voltage-gated calcium channels localize to?presynaptic nerve terminals and mediate key events?including synaptogenesis and neurotransmission.?While several kinases have been implicated in the modulation of calcium channels, their impact on presynaptic functions remains unclear. Here we report that the N-type calcium channel is a substrate for cyclin-dependent kinase 5 (Cdk5). The pore-forming α(1) subunit of the N-type calcium channel is phosphorylated in the C-terminal domain, and phosphorylation results in enhanced calcium influx due to increased channel open probability. Phosphorylation of the N-type calcium channel by Cdk5 facilitates neurotransmitter release and alters presynaptic plasticity by increasing the number of docked vesicles at the synaptic cleft. These effects are mediated by an altered interaction between N-type calcium channels and RIM1, which tethers presynaptic calcium channels to the active zone. Collectively, our results highlight a molecular mechanism by which N-type calcium channels are regulated by Cdk5 to affect presynaptic function. 相似文献